1. Field of the Invention
The present invention relates to an improved process for the liquid phase dehydration of 1-phenyl ethanol to produce styrene monomer. In particular, the invention relates to an improved process whereby the formation of undesirable by-products such as heavy condensation products is substantially reduced by incorporating in the liquid phase dehydration mixture an additive which is effective to reduce by-products make.
2. Description of the Prior Art
The dehydration of 1-phenyl ethanol to produce styrene is an important process which is widely practiced throughout the world. For example, in the Oxirane Process for the production of propylene oxide, 1-phenyl ethanol is a convenient co-product, and this material is advantageously converted to styrene monomer which is, of course, an industrial chemical of enormous commercial importance.
The dehydration of 1-phenyl ethanol is, itself, a well known reaction. For example, the vapor phase dehydration of 1-phenyl ethanol is described in U.S. Pat. No. 3,442,963 as well as in U.S. Pat. No. 3,658,928, and the liquid phase dehydration is described, for example, in U.S. Pat. No. 3,526,674.
From the standpoint of economics and efficiencies of operation, it is advantageous to conduct the 1-phenyl ethanol dehydration in the liquid phase in the presence of appropriate catalysts such as is described in U.S. Pat. No. 3,526,674. A disadvantage of such technologies is that a certain percentage of the feed material is converted to undesirable by-products such as heavy condensation products, and the production of these undesirable products lessens the economics and efficiency of the reaction.
It is desirable to reduce the formation of such by-products, and the present invention is specifically designed to accomplish this objective.